Caching writes was causing us some issues if the startup of
`lightningd` didn't complete, i.e., the writes would happen on the
live DB, but we'd forget about them. Since we have the backup.lock
file in same directory as the plugin is running in, we no longer have
to defer the writes. This hugely simplifies our logic.
Fixes#155
Changelog-Fixed: backup: The plugin doesn't lose sync anymore if the startup is interrupted
We were writing logs directly before killing `lightningd` which resulted in
the logs being lost. The subsequent check for the log-lines then would fail
obviously.
The node_factory from pyln-client clears the node directory when provisioning
a new node, which interferes with the backup-cli creation of the initial
snapshot. This just disables the cleaning until we can release the next
pyln-client version
